Jump to content

Stub Axle Oil Seal - Fit or leave off?


Turnips

Recommended Posts

As per the title:

I am rebuilding the front axle on my 1976 Series III 109. The vehicle appears to be modified as it has the later hubs and stub axles, I believe.

I think the stub axle should have a seal FRC3099 and a bronze bush FRC2928 - neither of which were present at disassembly. I did a bit of internet searching but could only find the discussion with regards to Defenders with one-shot grease in the swivels, and the ongoing discussion of leaving the seal and bush out to promote a flow of oil between the swivel and hub? Presumably this is why neither were fitted by the previous owner.

Opinions welcome!

parts book.jpg

stub axle.jpg

Link to comment
Share on other sites

1 hour ago, western said:

IIRC the bronze bush helps to support the driveshaft. 

It does and I would certainly be fitting one. The seals I am always in two minds about re the oil vs grease discussion!

Link to comment
Share on other sites

Absolutely fit the bush.  I’d omit the seal or fit it with the lip cut away to encourage oiling of the splines.  The wheel bearings don’t have any shortage of lubrication,  it the half shaft and drive flange so,Ines dry out even if greased and then wear and rust, accelerating wear.  Keeping them wet drastically reduces the issue.  Just be sure to add a smear of RTV sealant to the drive flange groove that retains the lip of the little plastic hub cone to stop it weeping oil and making a mess of the wheels and, worse, potentially contaminating your brakes.

  • Thanks 1
Link to comment
Share on other sites

Presumably the O-ring on the end of the drive flange is supposed to create a seal with the hub cone but doesn’t do a very good job, hence the need for rtv sealant?

thanks everyone for the input, long may the seal Vs no seal argument continue! 
 

I’m glad I asked anyway, but I do wonder why the previous owner omitted the bronze bushes.

Link to comment
Share on other sites

Hang on, do you have CV or UJ shafts? If these are stage one stub axles, then, yes, seal and bush, but if they're only UJ post rationalisation stub axles then only the seal is required. And it is required.

And it's usually fitted the wrong way around.

IMG_20211226_155430.jpg

Link to comment
Share on other sites

18 hours ago, Turnips said:

Presumably the O-ring on the end of the drive flange is supposed to create a seal with the hub cone but doesn’t do a very good job, hence the need for rtv sealant?

thanks everyone for the input, long may the seal Vs no seal argument continue! 
 

I’m glad I asked anyway, but I do wonder why the previous owner omitted the bronze bushes.

I got mixed up because of the Defender axle diagrams.  You shouldn’t need RTV for the steel hub cone if the O-rings are in good order.  It is for the plastic cones on coiler axles, which don’t use o-rings, that RTV is needed.

As for the seals, the seal inside the chalice neck separating swivel and diff oils is required to stop all the oil pooling at one end of the axle on side slopes and then staying there, but the stub axle seal is not important.  Series vehicles don’t seem to suffer as badly from worn splines on the drive flanges as Defenders, and that is possibly as much due to better quality metals as well as the lower engine torque, but wet splines will still fare better than dry.  If you do omit the seals, then keep an eye out for leaks through the hub cones - the seals will not only prevent oil from reaching the hub and drive flange, but the increase in adiabatic pressure, so the cones could get pooped off as the swivels warm up.  If that happens, use the RTV.

Link to comment
Share on other sites

My experience is that the seals are essential: I've lost two hub caps due to adriatic pressure in the flanges. Which is why I had to change the seals in mine.

  • Like 1
Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...

Important Information

We use cookies to ensure you get the best experience. By using our website you agree to our Cookie Policy